1. Field
Subject matter disclosed herein relates to aircraft communication, and more particularly, to a non line-of-sight communication path to augment a line-of-sight communication path.
2. Information
Flying aircraft may communicate to other aircraft or ground stations to convey a variety of information, such as the aircraft's position or velocity, mechanical state of the aircraft, and so on. Such information may be used for air traffic control or to relay weather or other flying conditions from aircraft to aircraft, for example. Methods of communicating information may involve wirelessly transmitting or receiving radio frequency (RF) signals among aircraft or ground-based stations.
Some methods of communication may be limited to situations where an RF receiver has a line of sight to an RF transmitter. One example is an automatic dependent surveillance-broadcast (ADS-B) system. For example, RF signals broadcast from an aircraft may be received by a radio receiver that is within a line-of-sight range of the broadcasting aircraft. A radio receiver may be located on another aircraft or at a ground-based station.
However, some situations may occur that limit or prevent line-of-sight communication. For example, aircraft operating in polar regions or other remote regions may be out of range (e.g., beyond line-of-sight range) of ground stations. For another example, aircraft may operate in areas that lack ground-based communication stations or other infrastructure. Building or providing ground stations in some of these areas may be expensive or even cost prohibitive. For yet another example, a mountain range may be located between a low-flying aircraft and a ground station. Techniques or approaches to address situations that limit or prevent line-of-sight communication may be desirable